Lever arm for switches, rheostats, and like electric devices



Nov. 13 1923. I 1,473,838

J. DRIESSEN LEVER ARM FOR SWITCHES, RHEOSTATS, 'AND, LIKE ELECTRIC DEVICES Filed July 1921' 3 Sheets-Sheet 1 J. DRIESSEN LEVER ARM FOR SWITCHES, RHEOSTATS, AND LIKE ELECTRIC DEVICES Filed July 6. 1921 5 Sheets-Sheet 2 Fig. 2

J. DRIESSEN LEVER ARM FOR SWITCHES, RHEOS TATS,

AND LIKE ELECTRIC DEVICES 3 Sheets-Sheet 5 Filed July 6, 1921 Patented Nov. 13, 1923. I

UNITED STATES JEAN DRIESSEN, OF PARIS, FRANCE.

LEVER ARM roe SWITCHES, nnnosra'rs, Ann LIKE LECTRIC DEVICES.

Application filed July 6,

To all whom it may concern:

Be it known that I, JEAN DRIESSEN, a citizen of the Republic of France, residing 'in Paris, France, have invented certain new' and useful Improvements in Lever Arms for Switches, Rheostats, and like Electric Devices; and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and. use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention relates to a lever arm device for switches, rheostats or like devices wherein the extra current spark is not produced between the contact pieces and the frictional member of the lever arm, but between a pair of carbons or the like which are readily renewable and are carried by the said lever arm, thus obviating all injury to the contact pieces.v For this purpose the lever arm is formed in two pieces which are insulated from and movable with reference to each other, each piece being provided with a carbon whereby an electric contact may be made between the two parts. Upon breaking the circuit of the current, the separation between the two portions of the lever arm and consequently oil? the said carbons is automatically effected by the stoppage of one of the parts against a stop-piece, causing the spark to pass between the carbons.

The following description together wit-h the accompanying drawings which are given by way of example, shows an embodiment of this invention.

Fig. 1 is a plan view of a rheostat lever arm, the said arni being in the position in which no current passes.

Fig. 2 is a plan view of the same arm in the position in which the current is passing.

Fig. 3 indicates the moment of breaking the circuit upon the separation of the two carbons.

Fig. 4 shows the contact between the carbons at the moment when'this contact has been produced.

Fig. 5 is a sectional view on the line X-X Fig. 1.

he switch lever is constituted by an arm a pivoted about the axle pin 6 and operated by hand or in like manner by the end 1921. Serial No. 482,775.

thereof 0, the other end (Z moving upon the row 01' contact pieces 6 mounted uponthe rheostat base The carbon piece 7L is inserted in a jaw which is carried by the arm a. The second part of the switch lever is constituted by an independent bent lever g pivoted upon the same axle pin 6, one arm thereof g carrying the carbon piece a which is mounted in a cylindrical portion wherein it is maintained by the screw This arm g is constantly drawn forward by the spring j secured at the other end to the rubber stop-piece is against which the switch lever is caused to bear when no current is passing. The movement of the lever produced by the spring is moreover limited by the arm g which enters in contact with the adjustable screw Z which is screwed into the stationary nut m.

The two parts a and g of the switch lever are separated from-each other as well as from the axle pin by an insulating washer 2, whereby the current in the positions shown in Figs. 2 and at will follow the path: contact piece 6, arm (a, carbon piece 71, carbon piece If, lever g. In this case, the device will operate as follows. If the frictional portion (Z is disposed upon the contact piece 6 which is the position for no current passing, Fig. 1, the carbon pieces b 702 will now be separated, inasmuch as the screw Z acts to limit the movement of the lever g in the counter-clockwise sense as pro duced by the spring 7'. It the switch lever is moved into the position shown in Fig. 3, the contact is now about to be made, and it is observed that the frictional portion is already partially disposed upon the contact piece 6 As soon as the carbon pieces h and it touch each other, the ele tric contact is established.

In Fig. 4:, the fiat strip (1 entirely covers the contact piece 6 and the lever arm g has now become slightly separated from the screw Z. In the other positions, Fig, 2, the lever is operated as a lever of the usual kind in a single piece, the spring j maintaining the carbons in constant contact with each other. In the succeeding step the current is broken by passing from the contact piece 6 to the contact piece 6 and it is still to be observed that the carbon pieces are separated by the effect of the stop-piece Z at the moment when the frictional piece cl is still in contact with the contact piece 0, Fig. 3, whereby the current will be broken precisely between the carbons, causing the spark to occur between the latter instead of between the frictional portion and the contact; piece 6 thereby obviating all injury to this latter.

The distance between, the carbons is adjusted. by causing the carbon 71 to slide in the lever arm and by securing it therein by means of the screw '6 making all adjustments in order to break the current as above mentioned.

It is obvious that without exceeding the limits (it this invention it may be suitably modified in detail, and for instance it may be applied to any other construction of switch or rheostat than the one just described.

I-Iaving now described my said invention and the best means I know 01'" cariagingr the same into effect, what I claim is:

In an electric switch, a series of slationary contacts. a pivoted switclrarm having a frictional member movable over the contacts, a bent lever pivoted on the axle of the switch-arm, carbons carried by the switch arm and lever. adapted to electrically connect the same, a return spring connected with the lever to maintain Contact between the carbons during the movement of the switch arm over the contacts, and an adjustable stop for engaging the lever, whereby the carbons will be separated and the circuit broken when the trictiomil member is still upon one of the contacts.

In testimony that I claim the foregoing as my invention, I have signed my name.

JEAN DRIESSEN. 

